Footage of French explorer Paul-Henri Nargeolet, one of passengers onboard submarine that went missing on way to Titanic
Paul-Henri Nargeolet, French explorer and director of underwater research at a company that owns the rights to the Titanic wreck, who is among the passengers onboard the submarine that went missing on trip to the wreckage, speaks during an interview in Paris, France, in this still image from an undated handout video obtained by Reuters on June 20, 2023. Reuters

French oceanographer Paul-Henri Nargeolet, one of the five people on board a submersible missing in the North Atlantic, is a world renowned expert with more than 35 dives to the Titanic shipwreck under his belt, his colleagues said on Wednesday.

"He is the world specialist on the Titanic, its conception, the shipwreck, he has dived in four corners of the world - he is a super-hero for us in France," said Mathieu Johann, his editor at Harper Collins.

Johann convinced Nargeolet to write his book 'In the depths of the Titanic' because he said his kids were super-fans.

Nargeolet, 77, went missing on Sunday along with four others on a tourist visit aboard the Titan submersible to see the wreck of the British ocean liner, which sank when it hit an iceberg on its maiden voyage in 1912 and now lies on the seabed at a depth of about 12,500 feet (3,810 meters).

A huge search and rescue operation is underway.

The underwater explorer needed convincing to write a book, Johann said, because he wanted to spend all of his time diving.

"He wakes up in the morning and he wants to go to the sea," said Johann.

CAREER IN FRENCH NAVY

Director of underwater research for RMS Titanic, which owns the rights to the ship's remains, Nargeolet started researching and exploring the Titanic wreck when he joined the French ocean research institute Ifremer in 1986, after a 22-year career in the French navy.

"He piloted the Nautile (a submersible that went to the wreckage). He is known for his great experience ... someone that is part of Ifremer history is aboard," said Olivier Lefort, oceanographic fleet operations director for the institute.

During his explorations of the wreck of the Titanic he brought about 5,500 objects to the surface, including personal items belonging to passengers, like binoculars and letters, said Johann.

He said the only part of the ship that the diver had not explored to date was the safe room, where gold and jewellery would have been kept.

The 1997 film "Titanic" directed by James Cameron, a friend of Nargeolet, was inspired by images taken by the French explorer, who was amazed by the quality of the reconstructions in the film, shot in a pool, Johann said.

Nargeolet's French wife, Anne, lives in Connecticut and his children live outside of France.

Nargeolet was previously married to American journalist Michele Marsh, who died in 2017. They met after Marsh contacted the explorer to ask for the contact of a Frenchman who had survived the Titanic.

The president of RMS Titanic, Jessica Sanders, said in a statement on Wednesday that Nargeolet's experience was unparalleled and "no-one has a better chance of navigating equipment failures than he does".

Bernard Cauvin, director of La Cite de la Mer nautical museum in Cherbourg, who has known Nargeolet since 2009, said: "He is someone extremely humble, and very serene, he was sure of himself but he was rigorous - he wouldn't have gone somewhere if he was unsure."

(Editing by Janet Lawrence)